一株产纤溶酶菌株的分离鉴定及其纤溶组分分析

Isolation and identification of a fibrinolytic enzyme producing bacterium and its analysis of the fibrinolytic components

【目的】筛选性能良好的产纤溶酶菌株,对菌株进行多项分类鉴定,分析其纤溶酶系的组成特征及纤溶能力。【方法】通过酪蛋白培养基初筛,琼脂-纤维蛋白双层平板复筛,从海泥、土壤等环境中筛选纤维蛋白降解菌,以尿激酶为标准测定纤溶酶活性。通过形态学、生理生化特征研究,结合16S rDNA基因序列分析菌株种类及系统分类地位。通过SDS-PAGE和纤维蛋白酶谱法分析胞外纤溶酶系的组成特征。【结果】筛选到一株能降解纤维蛋白的细菌CNY16,鉴定其为沙福芽孢杆菌(Bacillus safensis)。该酶为胞外酶,SDS-PAGE和纤维蛋白酶谱结果表明该纤溶酶系有至少两种分子量大小不同的纤溶酶,分别约33 kD和23 kD。能有效溶解血块中纤维蛋白,并且对红细胞无降解作用。【结论】细菌CNY16是一株新的纤溶酶产生菌,纤溶酶活性及稳定性较好,具有潜在开发价值。为获取新型纤溶酶提供了一种新的菌源。

[Objective] To isolate and identify a fibrinolytic enzyme producing bacterium, and to analyze the component and characteristic of fibrinolytic enzyme. [Methods] Plasmin-producing bacterium was isolated by casein medium and AGAR-fibrin double-layer tablets from sea mud, soil,etc. Then its enzyme activity was measured by urokinase standard curve. The morphological,biochemical and physiological characteristics and 16 S rDNA gene were analyzed to identify the taxonomic position of strain CNY16. The composition of the extracellular plasmin system was analyzed by SDS-PAGE and fiber protease zymogram. [Results] A strain named CNY16 withfibrinolytic activity was isolated and identified as Bacillus safensis. The results of SDS-PAGE and fiber protease zymogram showed that the extracellular fibrinolytic enzyme system contained at least two fibrinolytic enzymes with molecular masses of approximately 33 kD and 23 kD, respectively.The plasmin effectively dissolved fibrin clots, but did not hydrolyze blood cells. [Conclusion]CNY16 was a novel plasmin-producing bacterium, the fibrinolytic enzyme produced by strain CNY16 hold the valuable property in high activity and good stability. The strain might provide a new source for novel fibrinolytic enzymes.